"Danish felt he was a man and he did not like the restrictions his mother had placed on him," Harris said.

Minhas called police the morning of Nov. 25 to say he had come home from a night out to find his mother, 43-year-old Tabassum Kham, fatally stabbed.

Detectives determined Minhas agreed to pay Mohamed up to $4,000 for the killing, Harris said.

Both teens have admitted to their role in the killing, he said.

Minhas and Mohamed are both in custody, and neither has been assigned attorneys because they haven't made initial court appearances, Harris County District Attorney's office spokeswoman Donna Hawkins said.

Minhas' cousin, Atif Iqbal, said the family was devastated, first by Khan's death and now the murder charges.

“He was my brother. He was our son. He was everything,” he told the Houston Chronicle. “We put all of our efforts into nurturing him and his education. Never in my wildest dreams did we ever think about him like this.

“We fed him with a spoon made out of gold.” Harris described Kham as a “strict Muslim mother who followed her faith but not only that, no different from any other parent regardless of what faith or background they are, who set out rules for their children to follow.” He said Kham's rules were “very simple things,” such as the need to stick to a curfew, do chores, and stay off freeways.

He said Minhas had stayed out all night before calling police about finding his mother's body and that this “stood out to us almost immediately.” Minhas had no previous criminal record. He described himself on a social networking Web site as a native of Lahore, Pakistan, and said he was “loyal, trustworthy, ethical, all of the things a Boy Scout would be.”

Authorities said Minhas was in a law enforcement program at his high school and that the Houston police shield logo was the screen saver on his personal computer.

Mohamed initially attracted the attention of authorities when he was picked up Dec. 4 by school police for drug possession on campus, detectives said. Mohamed spoke to detectives about his friendship with Minhas, and that led police to seek search warrants.

Mohamed was arrested on the murder charge while at school. Minhas was arrested at a relative's home.

“At one point in the interview, he said: 'I loved my mother to death,'” Harris said of his questioning of Minhas. “I guess he meant that literally.”